Answer: true
Step-by-step explanation:
Z-tests are statistical calculations that can be used to compare the population mean to a sample mean The z-score is used to tellsbhow far in standard deviations a data point is from the mean of the data set. z-test compares a sample to a defined population and is typically used for dealing with problems relating to large samples (n > 30). Z-tests can also be used to test a hypothesis. Z-test is most useful when the standard deviation is known.
Like z-tests, t-tests are used to test a hypothesis, but a t-test asks whether a difference between the means of two groups is not likely to have occurred because of random chance. Usually, t-tests are used when dealing with problems with a small sample size (n < 30).
Both tests (z-tests and t-tests) are used in data with normal distribution (a sample data or population data that is evenly distributed around the mean).
Answer:
D
Step-by-step explanation:
There is 360* in a circle, so you would divide 360 by 20 to get 18.
2. 3. 5. are correct
1. and 4. are actually interchanged
Let n represent the amount Colin earned on Sunday.
On Sat. he earned n/2; on Sun. he earned n; and on Friday he earned (1/2)(n/2).
Then n/2 + n + n/4 = $70
Mult. all terms by 4 to eliminate fractions:
2n + 4n + n = $280
7n = $280 => n = $40
Colin earned n/2, or $20, on Saturday; n, or $40, on Sunday; and n/4, or $10, on Friday.
Note that $20 and $40 and $10 add up to $70, as they must.
